1. Field of the Invention
The present invention relates to an apparatus arranged for grinding, polishing, etc. with a closed loop of grinding, polishing etc. belt mounted on the output shaft of a motor and driven by a rotating drive wheel, said loop belt or endless belt being intended to be applied against a workpiece which is to be machined by means of the loop belt, said closed loop having loop portions differing from one another in a running direction, the loop being steered by steering members to adopt an essentially L-shape and comprising at least two loop portions, of which the loop portion which is arranged to make contact with said workpieces is preferably selected shorter than the other loop portion.
Particularly in continuous processes for machining of materials into finished products, there is a requirement for the machines which perform the machining to demand little space in order for room to be made available for all machines. The same requirement for compactness also often applies to individual machines. The above requirement is often coupled to a demand that the machining, closed belt loop or endless belt shall be long in order to ensure a long service life and effective machining during long working sessions without any or with only a few changes during each working session. In prior-art technology, long belt loops have involved a demand for a large space in order to contain the belt loop, particularly in the horizontal plane, since machining is frequently to be carried out on surfaces which are both horizontal and vertical or in between, for instance on window mouldings of wood, which are usually produced in a continuous process.
Long, endless belts in themselves give rise to certain problems in profile polishing, for instance with stability in the transverse direction to the direction of rotation of the belt. Because of this, the risk is incurred that the belt loop can easily migrate to the side of the workpiece, resulting in disruption of production and a need for action on the part of the personnel.